text: // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
  /******************************************************************************
   *
   * Module Name: exstorob - AML object store support, store to object
   *
   * Copyright (C) 2000 - 2021, Intel Corp.
   *
   *****************************************************************************/
  
  #include <acpi/acpi.h>
  #include "accommon.h"
  #include "acinterp.h"
  
  #define _COMPONENT          ACPI_EXECUTER
  ACPI_MODULE_NAME("exstorob")
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_store_buffer_to_buffer
   *
   * PARAMETERS:  source_desc         - Source object to copy
   *              target_desc         - Destination object of the copy
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Copy a buffer object to another buffer object.
   *
   ******************************************************************************/
  acpi_status
  acpi_ex_store_buffer_to_buffer(union acpi_operand_object *source_desc,
  			       union acpi_operand_object *target_desc)
  {
  	u32 length;
  	u8 *buffer;
  
  	ACPI_FUNCTION_TRACE_PTR(ex_store_buffer_to_buffer, source_desc);
  
  	/* If Source and Target are the same, just return */
  
  	if (source_desc == target_desc) {
  		return_ACPI_STATUS(AE_OK);
  	}
  
  	/* We know that source_desc is a buffer by now */
  
  	buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer);
  	length = source_desc->buffer.length;
  
  	/*
  	 * If target is a buffer of length zero or is a static buffer,
  	 * allocate a new buffer of the proper length
  	 */
  	if ((target_desc->buffer.length == 0) ||
  	    (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) {
  		target_desc->buffer.pointer = ACPI_ALLOCATE(length);
  		if (!target_desc->buffer.pointer) {
  			return_ACPI_STATUS(AE_NO_MEMORY);
  		}
  
  		target_desc->buffer.length = length;
  	}
  
  	/* Copy source buffer to target buffer */
  
  	if (length <= target_desc->buffer.length) {
  
  		/* Clear existing buffer and copy in the new one */
  
  		memset(target_desc->buffer.pointer, 0,
  		       target_desc->buffer.length);
  		memcpy(target_desc->buffer.pointer, buffer, length);
  
  #ifdef ACPI_OBSOLETE_BEHAVIOR
  		/*
  		 * NOTE: ACPI versions up to 3.0 specified that the buffer must be
  		 * truncated if the string is smaller than the buffer. However, "other"
  		 * implementations of ACPI never did this and thus became the defacto
  		 * standard. ACPI 3.0A changes this behavior such that the buffer
  		 * is no longer truncated.
  		 */
  
  		/*
  		 * OBSOLETE BEHAVIOR:
  		 * If the original source was a string, we must truncate the buffer,
  		 * according to the ACPI spec. Integer-to-Buffer and Buffer-to-Buffer
  		 * copy must not truncate the original buffer.
  		 */
  		if (original_src_type == ACPI_TYPE_STRING) {
  
  			/* Set the new length of the target */
  
  			target_desc->buffer.length = length;
  		}
  #endif
  	} else {
  		/* Truncate the source, copy only what will fit */
  
  		memcpy(target_desc->buffer.pointer, buffer,
  		       target_desc->buffer.length);
  
  		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  				  "Truncating source buffer from %X to %X\n",
  				  length, target_desc->buffer.length));
  	}
  
  	/* Copy flags */
  
  	target_desc->buffer.flags = source_desc->buffer.flags;
  	target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
  	return_ACPI_STATUS(AE_OK);
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_store_string_to_string
   *
   * PARAMETERS:  source_desc         - Source object to copy
   *              target_desc         - Destination object of the copy
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Copy a String object to another String object
   *
   ******************************************************************************/
  
  acpi_status
  acpi_ex_store_string_to_string(union acpi_operand_object *source_desc,
  			       union acpi_operand_object *target_desc)
  {
  	u32 length;
  	u8 *buffer;
  
  	ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc);
  
  	/* If Source and Target are the same, just return */
  
  	if (source_desc == target_desc) {
  		return_ACPI_STATUS(AE_OK);
  	}
  
  	/* We know that source_desc is a string by now */
  
  	buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer);
  	length = source_desc->string.length;
  
  	/*
  	 * Replace existing string value if it will fit and the string
  	 * pointer is not a static pointer (part of an ACPI table)
  	 */
  	if ((length < target_desc->string.length) &&
  	    (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
  		/*
  		 * String will fit in existing non-static buffer.
  		 * Clear old string and copy in the new one
  		 */
  		memset(target_desc->string.pointer, 0,
  		       (acpi_size)target_desc->string.length + 1);
  		memcpy(target_desc->string.pointer, buffer, length);
  	} else {
  		/*
  		 * Free the current buffer, then allocate a new buffer
  		 * large enough to hold the value
  		 */
  		if (target_desc->string.pointer &&
  		    (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
  
  			/* Only free if not a pointer into the DSDT */
  
  			ACPI_FREE(target_desc->string.pointer);
  		}
  
  		target_desc->string.pointer =
  		    ACPI_ALLOCATE_ZEROED((acpi_size)length + 1);
  
  		if (!target_desc->string.pointer) {
  			return_ACPI_STATUS(AE_NO_MEMORY);
  		}
  
  		target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
  		memcpy(target_desc->string.pointer, buffer, length);
  	}
  
  	/* Set the new target length */
  
  	target_desc->string.length = length;
  	return_ACPI_STATUS(AE_OK);
  }
  